This invention relates to lasers and more particularly to short wavelength lasers in the extreme ultraviolet x-ray spectral regions.
Heretofore stimulated emission of radiation has been obtained from solid state, gaseous, and chemical lasers as well as from semiconductors whose outputs are in the infrared visible and near ultraviolet wavelengths. Many attempts have been made to obtain lasers with an output in the x-ray region. One such U.S. Pat. No. 4,053,783 has been issued in which stimulated x-ray emission at 304 A has been proposed. This arrangement makes use of a pulsed helium-ion beam, stripped of electrons to its nuclei, which is directed upon a jet of hydrogen gas to cause a population inversion due to the resonant charge exchange between the ions and the hydrogen atoms in the gas jet.
Experimental results obtained in furthering the present invention are found in an article "Resonance Charge Transfer and Population Inversion Following C.sup.5+ and C.sup.6+ Interactions With Carbon in a Laser-Generated Plasma", by R. H. Dixon and R. C. Elton, Physical Review Letters, Vol. 38, pages 1072-1075, May 9, 1977, which is incorporated herein by reference.